TRACKING SCHOOLING FISH IN THREE DIMENSIONS*

Large schools of fish are observed to execute rich patterns of collective dynamics. The three-dimensional dynamics of schooling fish is a startling display of group behavior and continues to intrigue many scientists including fluid-dynamicists. Our current understanding of the physical and social principles underlying the emergence of coordinated group motion is limited due to a lack of three-dimensional experimental data. In this work, we perform three-dimensional tracking of a school of 2000 Harengula Clupeola (false herring) in the large 3,000 cubic meter tank in the aquarium of the Rotterdam Zoo. This tank reproduces a semi-natural tropical ecosystem, in which different fish species swim and interact in a relatively unconstrained environment. Here, we present an experimental setup and a tracking approach, which allows us to track the 2000 fish in the school. We use our dataset to derive quantitative metrics to characterize the variability of the school in terms of geometry, shape, internal structure and kinematics.